Shepard Tone

The Infinite Sound That Can Drive You Insane—Shepard Tones
The Action Lab
I've run into Shepard Tones before, enough so that I recognized the term, but that was all, so I did a little digging and came up with this video. The guy does a pretty good job of explaining how Shepard Tones work, but some reason I find him a little off-putting. Is it the tone of his voice, or maybe his affect (one of them terms that psychology has repurposed from it's original use)?

Via Language Log